Bug 822284 - Re-Disable browser_privatebrowsing_cookieacceptdialog.js & browser_privatebrowsing_crh.js on OS X for too many intermittent failures
Bug 772443 - Mark svg/as-image/svg-stylesheet-datauri-1.html as random for too many intermittent failures
Bug 823022 - Disable docshell/test/test_bug590573.html on Android for too many intermittent failures